United attempted to sign Herrera last summer but failed to complete a deal before the transfer window closed. Butt was part of the scouting team which helped former boss David Moyes continue to monitor the Spanish midfielder.

Herrera became United's first signing of the summer after the club activated his £28m release clause, and amid being linked with the likes of Juventus' Paul Pogba and new Real Madrid signing Toni Kroos, Butt says the club have been forced to compromise given the difficulty of signing a world class midfielder.

"His ability to pass and keep the ball is great," Butt, who awaits new over his role under Van Gaal this season, told the Manchester Evening News.

"You can see the Spaniard in him because they are always so comfortable on the ball. They can take the ball in any situation. It doesn't bother them. They want to keep the ball moving and play things simple. He looks like he will be a very good player for the club.

"He was at the level where you just had to take note of this player because there are not many top midfielders you can get, in my opinion.

"You can all talk about Paul Pogba or Toni Kroos or whoever but these kind of players are not easy to get. So you have to widen your net and Herrera is a bonus.

"He is at a level where he can play at a club like Manchester United and given a bit of time he can excel. He can become a star player for us.

"I do think he has the ability to do that. He can become a big influence on our midfield. You will have to be patient with him. You cannot expect miracles from him straight away just because there is a big price tag attached.

"That's not the lads fault. It is just the way football has gone. That's between the two clubs and shouldn't be allowed to put pressure on him.

"Given the time and the chance to develop, he can become a very good player. We think he can achieve very good things. It is a great signing for United and I am very pleased. I am sure the fans will take to him."

United have since added Luke Shaw to their squad since the confirmation of Herrera's arrival, and the club are expected to add further prior to the start of the season.